Behavior of young bulls in confinement housed separately or in group

Abstract

The objective of this study was to evaluate the behavior of young bulls (between September and October of 2003) and to associate this with their performance. Fifty crossbred animals were divided among three treatments: T1, with a pair of animals in each of 10 pens; T2, with 10 animals in individual stalls; and T3, with 20 animals in a collective pen. An adaptation period was followed by 5 d of observations, with annotations every 15 min between 6:00 and 20:00 h. The observed activities were ingestion, rumination and leisure. Dry and wet bulb temperatures, black glove temperature in shade and in the sun, and relative humidity were recorded at 10:00 and 15: h. Conditions of thermal comfort were also evaluated through the temperature and humidity index (THI). The mean THI value of 78.0 indicated the thermal discomfort of the animals. Time dedicated to ingestion by T1 animals (113.5 min) surpassed that of the other treatments (T2, 88.6 min and T3, 102.1 min). Ruminations time was similar for animals of T1 (121.3 min) and T2 (116.2 min), but greater than that of T3 (100.8 min). Leisure time of T1 animals (185.1 min) was less than those of T2 (215.1 min) and T3 (217.0 min). Animals of all the treatments preferred to ruminate while lying. Time spent lying was greater in individually housed animals (T2) and in those of the collective pen (T3). However, there were no significant differences among the treatments in the weight gain of the animals.